Sectoral Conical Beam Former for a 2 x 2 Array Antenna

Abstract

We propose a switched feed network for a 2 x 2 array antenna to form a sectoral conical beam. The proposed feed network, which is a symmetrical structure, consists of four 90 degrees hybrids, a crossover, and four 90 degrees delay lines. The prototype feed network and a 2 x 2 array antenna were fabricated on microstrip structures. The performance of the feed network was verified by measuring the radiation patterns at the center frequency of 2.57 GHz. The maximum radiation was measured at the 45 degrees elevation and at the 45 degrees, 135 degrees, 225 degrees, and 315 degrees azimuth angles, depending on the choice of the input port of the feed network.